Snap switch



Nov. 30,1926. 1509,22:

A. H. TRUMBULL SNAP SWITCH Filed August 11. 1922 A TTORNEYS.

- Patented Nov. 30, 1926.

UNITED STATES ALEXANDER H. TBUMBULL, OF STRATFOBD, CONNECTICUT, ASSIGNOBTO THE CON PATENT orriciz.

NECTICUT ELECTRIC HANUFACTURING COMPANY, OF BRIDGEPORT, CONNECTICUT,

A CORPORATION OF CONNECTICUT.

SNAP SWITCH.

Application filed August 11, 1922. Serial No. 581,173.

This invention relates to electrical switches and has for an object to.provide an improved switch mechanism of the snap action type which willbe positive and reliable in operation, and in which. there will be nodanger of the contacts freezing and thus causing failure of the switchto operate.

In carrying out my invention I provide in addition to the usual springoperating mechanism a positively acting means for imparting initialmovements to the contact carrier. thus the contacts are started with apositively operating means from the stationary position and thespringprovides quick movement for the remainder of the throw of the switchelements.

With the foregoing and other objects in view I have devised theconstructions illustrated in the accompanying drawing, in which- Fig. 1is a side elevation of one form of my switch with the contacts in oneextreme position.

Fig. 2 is a longitudinal sectional view on an enlarged scale through the"form of switch mechanism shown in Fig. 1, showing the positions of theelements immediately prior to initial movement of the contact carrier.

Fig. 3 is a transverse sectional view through the switch mechanism ofFigs. 1

and 2.

i Fig. 4 is a top plan view of another form of switch showing theapplication of my invention thereto.

Fig. 5 is a side elevation of the form of switch shown in Fig. 4 withthe contacts in one extreme position.

Fig. 6 is a longitudinal sectional view on an enlarged scale through theform of switch mechanism shown in Figs. 4 and 5 showing the positions ofthe elements immediately prior to initial movement of the contactcarrier.

Fig. 7 is a transverse sectional view through the switch mechanism ofFigs. 4, 5. and 6, and

Fig. 8 is a view of the contact blades and head upon which they aremounted;

In Figs. 1, 2, and 3 l have illustrated the principle of my invention asapplied to one form of switch operating mechanism the form shown beinga'push button switch. The switch mechanism is mounted upon a supportingyoke 46 secured to an insulating block 47 and provided with openingsthrough which push buttons 48 are guided for reciprocating movement.Between the buttons the yoke is provided with depending flanges or wings49 on which the switch mechanism is mounted. These wings are recessedadjacent the lower ends thereof to receive reduced portions 50 of pin 51upon which a pair of rockers 52v are mounted, t ese rockers also havingnotches adapted to receive reduced portions 53 of the pin 51 to form apivot therefor. 'lhese wings 49 are also provided with notches 54 inwhich is seated so as to pivot therein one edge of the contact carrier55 which has a central recess '56 for a purpose presently to bedescribed.-

The contact element 57 is secured to one end of this carrier and in thesame manner as in the first form.

Carried by and between the rockers 52 is a pin 58 having reduced ends 59seated in openings in these rockers and mounted on this pin is a coilspring 60 having oppositely extending free ends 61 projecting throughopenings 62 adjacent the free ends of the stirrup 63, this stirrup beingotthe same shape as that employed in the first form and seated at itsapex upon the edge of the contact carrier 55 opposite to its pivotaledge, The rockers 52 are provided with recesses 64 in which the stems 65secured to the push buttons are seated, these stems being also providedwith openings through which the guide arms 66 project and act as guidesduring the operation of the rockers when the buttons are reciprocated.On opposite sides of the contact carrier the rockers are provided withcum surfaces 67 and 8 which function the same as the cam surfaces 4-3 ofthe first form, the operation being as follows:

Assuming the switch element is at rest, as viewed in Fig. 1, pushinginwardly on. the lower push button will rotate the rockers 52'comiter-clockwise about their pivot pin 51 to the position shown in Fig.Qand as the center of the pin 58 carrying the spring is swung about thepivot 51 it will-move a greater distance from the free edge 69 of thecontact carrier. Therefore, the free arms of this Spring will be drawntogether winding the spring or putting it under tension until it reachesthe position shown in Fig. 2 where the center of the pin 58 passesthrough the center line 7 0 of the contact carrier. This will transferthe pull of the spring to the other side of this carrier and will swingthe free edge of the contact carrier about its pivotal ed e clockwise asviewed in this figure to s ift the contact element. At about the timethe center of pin 58 passes through this line the cam surface 67 engagesthe edge of the contact carrier as shown, and positively imparts theinitial movement to this member. After the contact has been swung,pressing on the other-push button will swing the rockers in the oppositedirection, the operation being exactly reversed with the cam 68imparting the initial movement to the contact carrier at about the timethe center of the pin 58 passes through the center line of the carrier.

Referring to the form of mechanism illustrated in Figs. 4, 5, 6, and 7,this mechanism is mounted within the recess 10 within an insulatingblock 11. The mechanism may be used on different types of switches butfor the purpose of illustration I have shown it as used with a singleswitch element 12 adapted to make electrical connection between the twostationary contacts 13 and 14 which are arranged to be connected to thelead wires, notshown, by suitable bindingposts 15, these bindingpostsand contacts being secured in the block by any suitable means, such asscrews 16.

The switch. operating mechanism is mounted in a supporting yoke 17 whichis secured to the insulating block by suitable;

screws extending through the same, not shown. This yoke is provided witha pair of spaced depending flanges or wings 18 by which the variousparts of the mechanism are carried. The contact carrier comprises a flatbridge piece 19 preferably of drawn stock and having a central notch 20therein for a purpose presently to be described. Se-

cured to one end of the bridge piece 19, as by upsetting the latter, isa head 21 of in sulating material to which is secured the contact blade22 by any suitable means, such as rivets 23. The carrier 19 has one edgethereof seated in notches in the wings 18 in which it may rock under theaction of the operating mechanism, there being inclined edges 25 leadingfrom these notches against which the contact carrier rests when in itsextreme positions.

Pivoted between the wings i8 by any suitable means, as pin 26, is arocker 27 provided with suitable operatingmeans such as I 30 to whichthe operating knob 28 is secured preferably by upsetting the inner endthereof. The stemof the knob is shouldered at 31 so that there may besecured between this shoulder and the crossbar an indicating plate 32-rovided with indications thereon such as On and Off which may beobserved through an opening 83 in the face plate 34. At their free endsthe sides 29 of the rocker are provided with notches 35 to receive apin'36, this pin being reduced at its ends as at 37 to provide bearingsto extend into these notches and provide shoulders to keep the pin inosition between the side members. Mounte on this in and between the sideinembers is a coi spring 38 having its free ends 39 projecting inopposite directions from-the body thereof and extending through openings40 adjacent the free ends of a stirrup 41. This stirrup is preferably apiece of sheet metal bent substantially V-shaped as shown in Fig. 6 andresting at its apex on the edge of the contact carrier 19 opposite theedge which is seated in the notches 24-. The side members 29 areprovided with transverse openings 42 therethrough through which thecontact carrier 19 extends and the inner side walls 43 thereof are solocated as to provide cam surfaces to engage thecontact carrier 19 onopposite sides thereof adjacent its swingin edge to impart to thismember its initia movements upon movement of the rocker to operate theswitch. This operation is as follows:

Assuming the switch is in closed position, as shown in Fig. 5, movementof the knob 27 upwardly will swing the rocker about its pivot 26. Thismovement will swing. the center of pin 36 carrying the spring 38 aboutthe pivot 26 and as the contact carrier remains stationary until theparts reach the position illustrated in Fig. 6, the distance between thefree edge of the contact carrier and the center of pin 36 will increaseduring this movement so that the free arms of the spring will be drawntogether by the stirrup and the spring will be wound or placed undertension. As the center of pin fidpasses through center line 45 of thecontact carrier the pull of the spring will be transferred to theopposite side of this center line and will swing the free edge of illthese cam surfaces, the right hand one as viewed in Fig. 6, will contactwith the right counterclockwise, as viewed in Fig. 6, and

impart its initial movement thereto. As this is a positive movement, ifthe contacts should tend to stick they would be loosened by this action,and allow the 'spring to act to quickly give the contacts their furthermovement. In other words, the spring is not depended upon 'to give theinitial movements to the contact element. The operation of the contactcarrier in the opposite direction is merely the reverse of the operationjust described upon movement of the knob 28 to the left orcounterclockwise as viewed in 'Fig. 6.

Having thus described the nature of my invention, what I claim is:

1. In a device of the character described, a support, a contact carriercomprisin a flat bridge piece pivotally mounted in said sup port on oneof its side edges, a rocker pivotally mounted in said support, operatingmeans connecting therocker and carrier including a spring, and inclinedcams carried by the rocker on opposite sides of the' contact carrierarranged to engage the free edge of the carrier on operation of therocker and by camming action thereon to impart the initial movements tothe carrier.

2. In a switch, an oscillating contact carrier, an oscillating rockerfor operating said carrier, :1 spring carried by said rocker eccentricto the axis of oscillation thereof and provided with arms extending onopposite sides of its connection with the rocker, a

stirrup connecting said arms with said contact carrier at a pointeccentric to the axis of oscillation of the latter, and means carried bythe rocker on opposite sides of the carrier arranged to positivelyimpart the initial movements to said carrier.

3. In a switch, an oscillating contact carrier. an oscillating rockerfor operating said carrier, a spring'carried by said rocker eccentric tothe axis of oscillation thereof, a stirrup connecting said spring withsaid contact carrier at a point eccentric to the axis of oscillation ofthe latter, and means connected with the rocker arranged to positive- 1yimpart the initial movement to the carrier.

4'. In a switch, an oscillating contact carricrfan oscillating rockerfor operating said carrier, and a spring device connecting'said carrierand rocker and engaging both of said parts at points eccentric to theaxes of oscillation thereof, said spring device comprisinc a coil springcarried by one of said parts, means for connecting the ends of saidspring with the other of said parts, the ends of said spring beingdisposed toward the point of connection of said connecting means withsaid last named part, and means car- 'ried by the rocker adapted toengage the carrier to positively impart the initial move,- ments to saidcarrier.

5. In aswitch', anoscillating contact carrier, an oscillating rocker foroperating said carrier, acoil spring carried by said rocker eccentric tothe axis of oscillation. thereof, means for connecting the ends of saidspring with said contact carrier at a point eccentric to the axis ofoscillation of the latter, said ends being disposed toward the point ofconnection of said connecting means with said contact carrier, and saidrocker being provided with a cam surface arranged to engage the carrierto impart the initial movement thereto.

'6. In a switch, an oscillating contact carrier, an oscillating rockerfor operating said carrier, a stud carried by said rocker eccentric tothe axis of oscillation thereof, a coil spring on said stud, means forconnecting the ends of said spring with said contact carrier at a pointeccentric to the axis of oscillation of the latter, said ends beingdisposed toward the point of connection of said connecting means withsaid contact carrier, and means carried by the rocker on opposite sidesof the carrier arranged to engage the said carrier to positively impartthe initial movements thereto.

7. In a switch, an oscillating contact carrier, an oscillating rockerfor operating said. carrier, a coil spring carried by one of said part-seccentric to the axis of oscillation thereof, a stirrup connecting theends of said spring with the other of said parts at a point eccentric tothe axis of oscillation of the latter,' and means connected with therocker arranged to engage the carrier to positively impart the initialmovements thereto.

8. In a switch, a support. a contact carrier comprising a fiat bridgepiece having one of its edges in rocking engagement with said support, arocker for operating-said contact carrier, a coil spring carried by saidrocker eccentric to the axis of oscillation thereof, a stirrupconnecting the ends of said spring with the opposite edge of said bridgepiece, and means carried by the rocker arranged to engage the swingingedge of the bridge piece to positively impart the initial movementthereto" 9. In a switch, an oscillating contact carrier, an oscillatingrocker for operating said carrier. a coil spring carried by said rockereccentric to the axis of oscillation thereof, a stirrup connecting theends of said spring with said contact carrier at a point eccentric tothe axis of oscillation of the latter, and means carried by the rockeron opposite sides of the carrier arranged to engage said carrier topositively impart the initial movements thereto.

10. In a switch, an oscillating contact carrier, an oscillating rockerfor operating said carrier, a coil spring carried by said rockereccentric to the axis of oscillation thereof, flexible stirrupconnecting the ends of said spring with said contact carrier at a ointeccentric to the axis of oscillation 0 the latter, and said rocker beingprovided with cam surfaces on opposite sides of said carrier arranged toengage the carrier to impart the initial movements theretol In testimonywhereof I aflix my signatuie.

ALEXANDER 'H. TRUMBULL.

